Question

Làm giúp em ạ

Answer 1

a) 6x²-9x³

b) 2x+3xy-7

c) x²+6x+9

d) x³-3x²y+3xy²-y³

Answer 2

`a)(3x^2).(2-3x)`

`=6x^2-9x^3`

`b)(6x^2y+9x^2y^2-21xy):3xy`

`=2x+3xy-7`

`c)(x+3)^2`

`=x^2+6x+9`

`d)(x-y)^3`

`=x^3-3x^2y`